3{62 -Tertiarybutoxy-decahydro-benz{8 E{9 indenes

ABSTRACT

Total synthesis of known progestationally active steroidal materials. The steroids can be synthesized depending on the particular starting reactants selected by employing as intermediates bicyclic compounds of the formula   WHEREIN M IS AN INTEGER HAVING A VALUE OF 1 TO 2; R4 is hydrogen or lower alkyl; Z is lower alkylenedioxy, CH(OR2) and carbonyl; R8 when taken alone is hydrogen; R9 when taken alone is lower alkoxycarbonyl, aryloxy-carbonyl, lower cycloalkyloxycarbonyl, carbonyl-halide, hydrogen, carboxy, formyl and methylene-X, where X is a leaving group and when taken together are methylene; with the proviso that when Z is carbonyl R8 when taken alone is hydrogen; R8 when taken alone is carbonyl halide, hydrogen, carboxy, formyl and methylene-X where X is a leaving group and when taken together are methylene and R2 is hydrogen, lower alkyl, lower alkoxy-lower alkyl, phenyl-lower alkyl, tetrahydropyranyl, lower alkanoyl, benzoyl, nitrobenzoyl, carboxy-lower alkanoyl, carboxy-benzoyl, trifluoroacetyl and camphorsulfonyl AND REACTING THEM IN THE CASE WHERE R8 and R9 taken together are methylene or R8 is hydrogen and R9 is methylene-X with Beta keto esters and other analogs of the formula   WHEREIN R8 is selected from the group consisting of   AND LOWER ALKYL; R7 is lower alkyl; R15 is selected from the group consisting of oxo, lower alkylenedioxy or (hydrogen and lower alkoxy); B is selected from the group consisting of lower alkoxy-carbonylmethylene, lower-aryloxy-carbonyl-methylene, cyanomethylene, lower alkyl sulfinyl-methylene, lower alkyl sulfonyl-methylene, and R25 and R26 are independently selected from the group consisting of hydrogen, hydroxyl and lower alkyl.

United States Patent [191 Hajos 1 .3B-TERTIARYBUTOXY-DECAHYDRO- BENZ[E]INDENES [75] Inventor: Zoltan George Hajos, Upper Montclair, NJ.

[73] Assignee: Hoffmann-La Roche Inc., Nutley,

[22] Filed: Oct. 4, 1968 [21] Appl. No.: 765,023

[52] US. Cl. 260/340.9; 260/340.7; 260/345.9; 260/397.4; 260/456 R; 260/468 G; 260/473 F; 260/487; 260/488 B; 260/514 G; 260/586 H [51] Int. Cl C07d 13/04 [58] Field of Search 260/340.9, 586 H [56] References Cited UNITED STATES PATENTS 3,019,252 [[1962 Nomine et al. 260/476 3,117,979 1/1964 Nomine et al. 260/340.9 3,413,314 11/1968 Amiard et al. 260/340.9

Primary ExaminerDonald G. Daus Assistant Examiner.lames H. Turnipseed Attorney, Agent, or Firm-Samuel I... Welt; Jon S. Saxe; George M. Gould [57] ABSTRACT Total synthesis of known progestationally active steroidal materials. The steroids can be synthesized depending on the particular starting reactants selected by employing as intermediates bicyclic compounds of the formula 3,. 7 l R 1" I )"1 M 5 Iv I I H e wherein m is an integer having a value of l to 2; R

[ July 29,1975

is hydrogen or lower alkyl; Z is lower alkylenedioxy, Cl-l(OR and carbonyl; R, when nitrobenzoyl, carboxy-lower alkanoyl, carboxy-benzoyl, trifluoroacetyl and camphorsulfonyl and reacting them in the case where R and R taken together are methylene or Rx is hydrogen and R is methylene-X with B-keto esters and other analogs of the formula wherein R is selected from the group consisting of T2 e t2 5 H en en.

and lower alkyl; R, is lower alkyl; 12, is selected from the group consisting of oxo, lower alkylenedioxy or (hydrogen and lower alkoxy); B is selected from. the group consisting of lower alkoxy-carbonylmethylene, lower-aryloxy-carbonyl-methylene, cyanomethylene, lower alkyl sulfinyl-methylene, lower alkyl sulfonyl-methylene, and R and R are independently selected from the group consisting of hydrogen, hydroxyl and lower alkyl.

3 Claims, No Drawings and methylene-X 3 BTERTIARYBUTOXY-DECAI-IYDRO- BENZ[E]INDENES BACKGROUND OF THE INVENTION In recent years, much effort has been devoted to the 5 total synthesis of steroids. The present invention relates to certain polycyclic compounds and processes for their synthesis. The novel intermediates and processes of this invention provide a new synthetic route for the preparation of pharmaceutically valuable steroids.

SUMMARY OF THE INVENTION In one aspect, this invention relates to a process for preparing intermediates useful in the preparation of tricyclic compounds of the formula wherein R is hydrogen or lower alkyl; R., is hydrogen or lower alkyl; Z is defined hereinafter; m is an integer having the value of 1 or 2. Another aspect of this invention relates to a process for preparing intermediates which enable the direct 0 preparation of steroids of the formulae wherein m is an integer having a value of l or 2; R

is hydrogen or lower alkyl; Z is lower alkylenedioxy, CI-I(OR and carbonyl; R when taken alone is hydrogen; R9 when taken alone is lower alkoxycarbonyl, aryloxy-carbonyl, lower cycloalkyloxycarbonyl, carbonyl-halide, hydrogen, car-- boxy, formyl and methylene-X, where X is a leaving group and when taken together are methylene;- with the proviso that when Z is carbonyl, R when taken alone is hydrogen; R when taken alone is carbonyl halide, hydrogen, carboxy, formyl and methylene-X where X is a leaving group and when taken together are methylene and R is hydrogen, lower alkyl, lower alkoxy-lower alkyl, phenyl-lower alkyl, tetrahydropyranyl, lower alkanoyl, benzoyl, nitrobenzoyl, carboxy-lower alkanoyl, carboxybenzoyl, trifluoroacety and'camphorsulfonyl and reacting them in the case where R; and R taken together are methylene or R is hydrogen and R is methylene-X with ,B-keto esters'and other analogs of the formula 0 H li -C-B v wherein R is selected from the group consisting of I R7 fi CH- as CH2 and lower alkyl; R, is lower alkyl;

R is selected from the group consisting of oxo,

lower alkylenedioxy or (hydrogen and lower alkoxy); B is selected from the group consisting of lower alkoxy-carbonyl-methylene, lower-aryloxycarbonyl-methylene, cyanomethylene, lower alkyl sulfinyl-methylene, lower alkyl sulfonyl-methylene, and R and R are independently selected from the group consisting of hydrogen, hydroxyl and lower alkyl.

In still another aspect, this invention relates to the preparation of the compounds of formula III above wherein R is hydrogen, by reacting the compounds of formulae IV-a and IV-c with a vinylogous cyclic-betaketo compound of the formula:

wherein B is selected from the group consisting of lower alkoxy carbonyl-methylene, lower 'aryloxy carbonyl-methylene, lower alkyl sulfinylmethylene and lower alkyl sulfonyl-methylene.

Structure III can also be obtained starting with a compound of the formula V, in which R has been chosen to be oxo by reaction with compounds of the formulae IV-a and IV-c 3 A further aspect of this invention relates to novel intermediates of the formula IV. Subgeneric to the bicyclic compound of formula IV above are compounds of the formulae:

Rs H j IV I i 'cno l i H G'IZX e @1 5 Ififflzl IV (6) it COZR'S Tenant IV O i H doY wherein R.,, Z, m and X are as defined aforesaid; Y is selected from the group consisting of fluorine, chlorine, bromine and iodine and R;, is selected from the group consisting of lower alkyl, lower cycloalkyl and aryl.

DETAILED DESCRIPTION OF THE INVENTION In one aspect, this invention is concerned with novel indanones of the formulae IV, IV-a, [V-b, IV-c, IV-d, IV-e and lV-f which are useful as chemical intermediates as described herein. Also, certain of the keto comthe designation of such compounds by chemical nomenclature, the desired enantiomeric form is shown or designated. However, unless explicitly indicated otherwise, such illustration and designation should be taken as comprehending the enantiomer shown or designated, as well as its optical antipode or their corresponding racemate. In the formulae presented herein, the various substituents on cyclic compounds are joined to the cyclic nucleus by one of two notations, a solid line indicating a substituent which is in the ,B-orientation (i.e., above the plane of the paper), or a dotted line indicating a substituent which is in the a-orientation (below the plane of the paper).

As used herein, the term lower alkyl comprehends both side and branched chain hydrocarbon moieties such as methyl, ethyl, isopropyl, n-propyl, t-butyl and the like, having I to 7 carbon atoms in the chain. The preferred compounds are those derivatives wherein R is methyl, ethyl and propyl which can be converted into steroids which exhibit exceptionally active pharmacological properties as hereinafter described. The formative lower alkyl when used in expressions such as lower alkoxy-lower alkyl have the same significance. Thus, exemplary of the expression lower alkoxy-lower alkyl is oz-ethoxy-ethyl and 3-propoxy-propyl. Exemplary of lower alkanoyl are acetyl and propionyl or other residues derived from lower alkane carboxylic acids of 1 to 6 carbon atoms; lower alkylenedioxy is understood to mean alkylene of l to 6 carbon atoms exemplary of which is ethylenedioxy. The term nitrobenzoyl as used herein comprehends benzo moieties containing one or more aromatic nitrile substituents, for example, nitrobenzoyl moieties such as 4- nitrobenzoyl and di-nitrobenzoyl moieties such as 3,5- dinitrobenzoyl. The expression carboxy-lower alkanoyl comprehends di-basic aliphatic acids of l to 7 carbon atoms absent one OH moiety. Similarly, the expression carboxy-benzoyl denotes, for example, phthalic acids absent one OH moiety. The expression halide or halogen" comprehends chlorine, fluorine, bromine and iodine. The expression lower alkoxy as utilized herein designates a lower alkyl ether group such as methoxy, ethoxy and the like, wherein the alkyl group is as defined above. The term lower alkoxy carbonyl methylene includes for example, ethoxy carbonylmethylene. The term lower aryloxy carbonyl methylene includes for example, phenyloxy carbonyl methylene. The term aryl comprehends phenyl or phenyl having one or more substituents selected from the group consisting of lower alkyl, lower alkoxy, nitro, amine and halogen. The expression lower alkylaryl comprehends, for example, tolyl and ethylphenyl. The term cycloalkyl includes rings containing from I to 6 atoms, for example, cycloalkyl and cyclopentyl. Especially preferred compounds of formula IV are those wherein Z is lower alkoxy, especially t-butoxy although the other derivatives defined hereinabove such as, tetrahydropyranyloxy can be suitably employed in accordance with the process of this invention.

The following schematicflow sheet entitled Reaction Scheme A, exemplifies the process'routes employed in accordance with the teachings of this invention for preparation via process routes (1), (2), (3), (4), (5), (6), (7), (8), (9) and (10), the key intermedi- 5 ates of the formulae IV-c and lV-a, each of which can independently be reacted with the B-keto esters and other analogs thereof of formula V to yield the endproducts of formulae 1, II and III as hereinafter detailed.

Thus, in one aspect of the process of this invention, comprises preparing compounds of the formula IV'a by the general reaction steps (1), (2) and (4) of Reaction Scheme A to which the numerals and letters in parenthesis are referenced in the following descriptions.

Many of the indanone starting reactants of formula (fHghJ OOR'g El za Vll wherein Z is carbonyl are known. They may be conveniently synthesized by methods known in the art, for example, by the Michael Addition of methyl-vinylketone to 2-lower alkyl-cyclopentane-l,3-dione. The cyclization can be effected using pyrrolidine in a benzene solvent under reflux reaction conditions (cf., U.S.

Pat. No. 3,321,488). If desired, otherderivatives of formula VII may be prepared. For example, in order to prepare the derivatives wherein Zis hydroxy, the corresponding oxo group can be selectively reduced with lithium aluminum tri-(lower alkoxy)-hydride or sodium borohydride at low temperatures. Derivatives wherein 6 Z is lower alkoxy, for example, tertiarybutoxy, can be obtained from the corresponding hydroxy derivative by reaction under acid conditions with isobutylene by means known in the art. l-Carboxy-lower alkanoyl derivatives of formula VII-can be conveniently obtained by reacting dibasic lower alkanoic acids such as, succinic acid and phthalic acid and the like, with corresponding compounds containing the hydroxymethylene moiety. Other derivatives in accordance 10 with the definition of Z canbe obtained by methods known to those skilled in the art.

{1i el QH vIII H CH2 wherein R.,, Z, m, R;,, X and Y are as defined aforesaid.

The bicyclic ketone of formula VII can be converted Y to acid compounds of formula VIII by reaction in accordance with Step (1) of Reaction Scheme A with a base sufficiently strong to afford the corresponding anion of the bicyclic compound via conjugate enolate formation. Exemplary of the suitable bases for this reaction are alkali metal amides such as sodium amide and the'-like;, alkali metal alkoxides such as lithium methoxide and the like and alkali metal hydrides such as sodium hydride. Generally, it is preferred to conduct this reaction at room temperature although temperatures from about 40C. to the boiling point of the reaction mixture can be utilized. The reaction is come niently carried outin liquid ammonia or in the presence of an organic solvent inert to the reactants such as dimethylsulfoxide, dimethylformamide; hydrocarbons, e.g., benzene and toluene; and ethers, e.g., diethylether and tetrahydrofuran. A preferred solvent, for this reaction is dimethylsulfoxide. This intermediate enolate bicyclic reaction product can be isolated by conventional techniques such as, for example, by removal of the sovlent using vacuum distillation.

The anion which is thus obtained as a residue can be carboxylated by reaction with excess carbon dioxide to afford the 4-indane carbocyclic acid of the formula VIII. The carboxylation can be suitably effected by employing solid carbon dioxide in the form of dry ice or passing gaseous carbon dioxide into the reaction medium. Exemplary of the desirable solvents for this reaction are any of the aforementioned listed solvents which can be employed to prepare the anion with the exception of liquid ammonia, which is basic and dimethylsulfoxide, which tends to promote decarboxylation. In cases wherein liquid'ammonia or dimethylsulfoxide is employed to prepare the anion, an inert solvent should be substituted when conducting the carbonation reaction. Suitable reaction temperatures are in the range of 60C and about 40C. A preferred operating temperature range is l525C. Separation of the desired reaction product from the reaction medium can be effected by extraction. The extraction is suitably conducted in a hydrocarbon solvent in the presence of a dilute base such as sodium hydroxide or lithium carbonate to form the corresponding water soluble salt of the acid. Base extraction is employed so as to remove the desired product from the starting material. The aqueous layer is separated and carefully acidified to a pH of between 2.5 and 4.5 with dilute mineral acid and the desired product is then obtained by conventional techniques. Although the reaction can be suitably conducted at atmospheric pressure, increased yields can be obtained by conducting the reaction under higher pressures, e.g., in the range of 450 to 550 psi. Carboxylation takes place only at C-4 position on the indane nucleus in agreement with the preference for heteroannular conjugate anion formation with compound VII.

Inasmuch as the ultimate goal of this invention is to produce a compound of the formula I containing a 9baconfiguration, it is clear that the hydrogenation of the compound of formula VIII in accordance with Step (2) of Reaction Scheme A must predominantly proceed so as to yield a trans-hydrogenation product with respect to the two rings of the S-indanone or the corresponding Z-naphthalenone compounds. A feature of this invention is that the desired hydrogenation to yield a transfused bicyclic structure can be effected in extremely high yields. The hydrogenation is conducted in the presence of a catalyst preferably a noble metal catalyst, such as palladium, rhodium, irridium, platinum and the like. Especially preferred is the palladium catalyst. The noble metal catalyst can be utilized with or without a carrier and if a carrier is used, conventional carriers are suitable. It is preferred to use palladium on barium or calcium sulfate. Especially preferred is l0 percent. Pd/BaSO.,. The ratio of catalyst to substrate is notcritical and can be varied. However, it has been found advantageous to use a weight ratio of catalyst to substrate s from about l:l to aboutl:l0, Especially preferred is a ratio of 1:3. The hydrogenation is suitably effected in the presence of an inertorganic solvent for the particular compound of formula VII being hydrogenated, for example, a lower alkanol, such as methanol, isopropanol. or octanol; ketones for example, lower alkyl ketones such as acetone or methylethyl ketone; lower alkyl esters of lower alkanoic acids'such as ethyl acetate; lower alkyl ethers such as diethyl ether to tetrahydrofuran; aromatic hydrocarbons such as toluene or benzene and the like. It is especially preferred to conduct the hydrogenation using a lower alkanol as the solvent and it is preferably conducted under non-acidic conditions. Suitably, the hydrogenation is conducted under neutral conditions. It can be conducted at atmospheric pressure or below or above atmospheric pressure, for example, at pressures of as high as about 50 atmosphere. Also, the hydrogenation can be conducted at room temperature or temperatures above or below room temperature. As a matter of convenience, it is preferred to conduct the hydrogenation at room temperature. The hydrogenation is effected by utilizing conventional techniques, for example, the hydrogenation should be stopped after the uptake of the equivalent of hydrogen or if the absorption of hydrogen ceases before the uptake of an equivalent of hydrogen, it is advantageous to then add more catalyst and further hydrogenate. It will be appreciated that another significant aspect of this hydrogenation step lies in that the hydrogenation of the compound of formula VIII to afford the compound of formula IV-f proceeds without substantial decarboxylation of the substituted indane of formula VIII. Depending on the hydrogenation conditions used, the group represented by Z in formula VIII can be modified during the hydrogenation. For example, under the above-described hydrogenation conditions, when Z is OR and R is a group such as alkoxylower alkyl or tetrahydropyranyl, such group can be split, off during the hydrogenation procedure. A preferred group for R in which to conduct the hydrogenation and many of the subsequent other reactions is alkyl, especially, t-butyl.

The thus obtained saturated compound of formula IV-f can be converted to the 4-methylene-trans-fused compounds of formula IV-a by employing a modified Mannich-type reaction in accordance with Step (4) of Reaction Scheme A. The conversion can be effected using formaldehyde in the presence of a primary or secondary amine salts. Suitable salts which may be employed are those derived from strong mineral or organic acids such as for example, hydrogen halides, preferably as the chloride, sulfuric acid, oxalic acid and the like, such as for example, piperidine hydrochloride. The reaction can be suitably carried out at a temperature range of from 0 to about C. A preferred temperature range for this reaction is l540C. While the ratio of reactants used for the reaction is not critical, it has been found advantageous to use approximately a 10:1 molar ratio of formaldehyde to keto acid and a 0.1:1 to 1:1 molar ratio of amine to keto acid.

The reaction is best effected in a'dimethylsulfoxide solvent which functions both as a solvent for the reaction and also as a decarboxylating agent. Most advantageous results are obtained by allowing the compound of formula IV-f to deca'rboxylate in the dimethylsulfoxide solvent so-a'sto' form the corresponding anion formed by the addition of formaldehyde and primary or secondary amine salt. Aqueous formalin (37 per cent-40 per cent) is a generally satisfactory source of formaldehyde for this reaction. Exemplary of the amines suitable for this reaction include heterocyclic amines such as morpholine, piperidine and pyrrolidine; monoamines such as methylamine, butylamine and benzylamine. An especially preferred amine for this reaction is piperidine. Other polar solvents such as, for example, dimethylformamide and hexamethylphosphoramide which are inert to the reactants may be employed in conjunction with the dimethylsulfoxide. The dimethylsulfoxide solvent promotes decarboxylation and anion formation at the bicyclic 04 position notwithstanding the known preferential tendency of these compounds to enolize in the direction of the bicyclic C-6 position.

In another aspect of this invention in accordance with Reaction Scheme A, compounds of Formula IV-c may be prepared by alternate process routes (3 9), *9), (5 10) and (5 +6 8).

Thus, the compounds of formula IV-e can be prepared in accordance with Step (5) from the B-keto acids of formula IV-f in excellent yields employing an organic or inorganic acyl halide preferably thionyl halide, e.g., thionyl chloride; phosphorous trihalide, preferably phosphorous trichloride and phosphorous pentahalide, preferably phosphorous pentachloride. Thionyl chloride is particularly convenient since the byproducts formed are gases and can be easily separated from the acid chloride. Any excess of the low boiling thionyl chloride can be easily removed by distillation. This substitution reaction was successfully effected notwithstanding the known prior art [cf., C. B. Hurd et al., J. Am. Chem. Soc. 62, 1548, (1940)] which teaches the inability to prepare B-keto acyl halides by conventional reaction techniques from the corresponding ,B-keto acids. The reaction is suitably conducted at a temperature of from 0C to the boiling point of the solvent. Suitable solvents for the conversion are thionyl chloride (neat) or in an inert organic solvent such as, for example, benzene, toluene, hexane, cyclohexane and the like.

4-Carbonyl halide indanone compounds of formula IV-e, can be converted to the corresponding esters of formula IV-d by means known in the art. Preferred esters are those wherein R;; is lower alkyl, especially methyl and ethyl. The esters can be conveniently obtained by reacting the halide with an alkali alkoxide, e.g., sodium methoxide in a solvent such as, for example, lower alcohol, e.g., methanol and the like. Alternatively, the esters of formula IV-d may be obtained by reacting the halide with carbonyl diimidazolide in tetrahydrofuran solvent, then further reacting the thus obtained product with the desired aliphatic or aryl alcohol, e.g., phenol, methanol, ethanol and the like at room temperature to the reflux temperature of the solvent in, for example, tetrahydrofuran to obtain the desired ester.

As a further alternate wherein it is desired to prepare 4-alkoxy carbonyl indanones of formula IV-d, the conversion can be effected by treatment of the acids of formula IV-f with an ethereal solution of a diazoalkane such as diazomethane by known means. The reagent is a yellow gas and small quantities can be prepared conveniently prior to use in the form of a solution in ether. When the yellow ethereal solution is added in portions to a solution or suspension of the acid in ether at room temperature, nitrogen is evolved at once and the yellow color is discharged. When the yellow color persists, which is an indication that excess diazomethanehas been added, the solution can be heated, e.g., on a steam bath to expel excess reagent. Since the only by-product is a gas, a solution of the desired ester in ether results.

The esters of formula IV-d can also'be prepared by first esterifying the unsaturated acid compounds of formula VIII to compounds of formula VIII-a in accordance with Reaction Scheme A by the aforementioned methods and then catalytically hydrogenating this unsaturated ester. The steric course of this hydrogenation proceeds so as to yield the C/D-trans-hydrogenated product. Thus, an identical product of the structure of formula IV-d with C/D-trans-ring fusion is obtained in a similar manner to the case wherein the acid'of formula VIII is employed directly as the starting reactant for the hydrogenation step. The bicyclic C/D-transstructure obtained by the catalytic hydrogenation of the ester may be explained (although applicant is not bound by this theory) by postulating a chelated dienol ester intermediate formed from the non-enolic unsaturated B-keto ester on the surface of the catalyst. However, it should be noted that the rate of catalytic hydrogenation of the ,B-keto acid of formula VIII was approximately four times as rapid as was the case when the corresponding ,B-keto ester was employed, as the reactant. However, hydrogenation of the ester employing approximately three times the amount of catalyst employed in the case of the acid under identical reaction conditions resulted in an approximately equal hydrogenation rate.

The B-keto aldehydes of formula lV-b can be prepared from the acid halides of formula IV-e in accordance with Step (6) of Reaction Scheme A employing a reducing agent such as, lithium aluminum tritertiarybutoxyhydride. The reaction can be carried out in an inert aprotic organic solvent such as, ethers, e.g., tetrahydrofuran and hydrocarbons, e.g., toluene and hexane at a temperature range of l0C. to C., preferably between the temperature range of 20C. and -40C. When the reaction is carried out within the aforesaid defined temperature ranges, selective reduction of the acid halide can be effected without attacking the free keto group on the 5-position of the indane of formula IV-e. An alternative method of transforming the acid halide to the corresponding aldehydes can be accomplished by the catalytic hydrogenation of the acid chloride by-the Rosenmund Reaction. The technique introduced by Rosenmund consists in adding a small amount of a poisoning agent containing sulfur to the hydrogen catalyst system.

The indanones of formula IV-c wherein R.,, Z and m are as defined as aforesaid can be conveniently prepared in accordance with Steps (8), (9) and (10) of Reaction Scheme A depending upon the nature of X, from the esters of formula IV-d, the acid halides of formula IV-e or the aldehydes of formula IV-b.

Suitable requirements for the leaving group as defined by X in the compounds of formula IV-c are that it should function efficaciously in this process aspect, that is, that it be a suitable leaving group for the process of the present invention. Suitable groups which may be employed to form leaving groups are lower alkyl-aryl sulfonyloxy groups such as, for example, tosyloxy; arylsulfonyloxy groups such as, for example, benzene sulfonyloxy; lower alkyl sulfonyloxy groups such as, for

example, mesyloxy (methane sulfonyl); lower alkyl sulfinyloxy; halogen; an acyloxy radical derived from an organic carboxylic acid having 1 to 7 carbon atoms such as lower alkanoic acid, e.g., acetic acid and butyric acid; aryl carboxylic acids such as pphenylbenzoic acid and benzoic acid and cycloalkyl carboxylic acids such as cyclopentyl carboxylic acids. Other suitable leaving groups may be selected from the group consisting of wherein each of R and R is independently selected from the group consisting of lower alkyl, aryl and hydrogen, and R and R when taken together to the nitrogen atom to which they are joined, form a 5- or 6- membered heterocyclic ring structure. Thus, the

amino grouping represents secondary and tertiaryamino radicals. It includes monoalkylamino radicals, such as, for example, methyleneamino and butylamino; dialkylamino radicals such as, for example, dimethylamino and dipropylamino, heterocyclic amino radicals, such as, for example, pyrolidino, piperidino, morpholino and 4-methyl-piperizino. The amino radical may also be employed as a leaving group in a modified form by alkylation by known means with a suitable organic ester such as, for example, lower alkyl halide, e.g., methyl chloride or a hydrohalic acid such as, for example, hydrogen chloride to form the corresponding quaternary ammonium salt of the formula accordance with Step (9) of Reaction Scheme A by a reaction sequence which comprises first protecting the 5,-oxo moiety on the indanone, reducing the ester group to the corresponding 4-hydroxy methylene derivative, removing the protecting group before or after conversion to the desired derivative of formula IV'c.'Protection can be effected by converting the free oxo group to a cyclic ketal, e.g., a dioxolane ring system by reaction with a suitable lower alkylenedioxy containing compound, e.g., ethylene glycol or to an open ketal with for example, tri-lower alkyl orthoformates. The free oxo moiety can be regenerated after reduction of the 4-ester compounds of formula lV-d to the corresponding 4-hydroxy methylene compounds. A preferred protecting group is the dimethoxy derivative which can suitably be obtained by etherification with trimethyl orthoformate. The thus protected 4a-ester can be reduced employing for example, a suitable reducing agent such as, diisobutyl aluminum hydride to yield the 4-hydroxy methylene compound of the formula IV-c-l wherein R Z and m are as defined aforesaid.

Alternatively, the ester of formula IV-d in the protected form obtained as described above may be reduced to the alcohol of formula IV-c-l using an alkali metal reducing agent such as sodium metal and lower alcohol or lithium aluminum hydride. Compounds of formula IV-c wherein the leaving group X is lower alkyl sulfonyloxy or lower alkyl-arylsulfonyloxy can be prepared by esterification with an organic sulfonylhalide such as, for example, toluenesulfonyl halide, especially, p-toluenesulfonyl chloride to prepare the tosyloxy derivative or lower alkyl sulfonyl halides, especially methane sulfonyl chloride to prepare the mesyloxy derivative. The above reactions can be suitably conducted at a temperature range of -l0C to +10C in the presence of an organic base such as, for example, pyridine by methods known in the art. The corresponding sulfonic acids may also suitably be employed to effect the esterification in lieu of the sulfonyl halide. Leaving groups wherein X is lower alkyl sulfinyloxy may be obtained in an analogous manner to that above by employing the corresponding sulfinyl halides.

Leaving groups wherein X is defined by the grouping wherein R and R are defined as aforesaid can be convenientlyobtained from the acid halides of formula IV-e in accordance with process route 10) of Reaction Scheme A by a reaction sequence which comprises the steps of (a) reacting the compounds'of formula IV-e 13 '14 v t with a primary or secondary aliphatic or aromatic ample, a lower. alkyl halide such as methyl chloride.

amine of the formula a V v Leaving groups wherein X is definedby the grouping 2:122:3 eans to form the corresponding amlde of wherein-at least ithF 2o and R21 is hydrogen, may also be prepared from the aldehydes of formula lV-b in 4 Z- accordance with process route (8) of Reaction Scheme 10 A by selective condensation with a primary, amine of the formula I-I NR to form by known means the 7 novel imino Shiff Base intermediate of the formula 15. i y r z .1? c i 21 wherein R Z, m and R and R areas defined aforesaid; I 20 (b) protecting the 5-oxo group of the compounds of a 'j by fol-[mpg the i analog m a f wherein R,, Z, m and R are as defined aforesaid. ner similar to that previously described; (c) reducing The ald imines of formula can be co-mm 25 ether solvent such as, for example, tetrahydrofuran z jg g 2 325;: g define d as halogen may whlc.h upon.removal.of h protecting group by means be conveniently obtained from the alcohols 'of formula of dilute mineral acid yields a compound of the forby reaction with for examplemydrogen halides, mula: e.g., hydrogen chloride, phosphorous halides or thionyl /z, chloride by means known in the art.' Leaving groups H?)m wherein X is acyloxy as defined aforesaid may be suit- T ably obtained from the compounds of formula IV-c-l by reaction with the desired organic carl gtylic acid in i the presence of a mineral acid such as sulfuric acid or hydrochloric acid at reflux temperature by means H known in the art.

2o In another aspect, the process of this invention re- HZN lates to the preparation of compounds of the formulae 40 I, II and III by reaction of a B-keto ester or other analog 21 of formula V with compounds of formulae lV-c and wherein R,,, Z, m, R and R are as defined afore- IV-a in accordance with Reaction Scheme B. It should said. be appreciated that compounds of the formulae lV-a The compounds of formula IV-c-3 can be converted to and IV-c can be used interchangeably in all of the heretheir quaternary salt adducts by alkylation with for exinafter process reactions.

(See Reaction scheme D) The process of this invention in this aspect, comprises employing the bicycliciindanone derivativesof formulae IV-a and IV-c prepared as aforesaid and reacting them with certain subgeneric compounds encompassed by generic compounds of the formula V-b in accordance with process route (11) of Reaction Scheme 8' to prepare the benz[e]indene compounds of formula-I. Alternatively, for other subgeneric compounds encompassed by generic formula V-a in accordance with process routes ('12) and (13) of Reaction SchemeB, the steroids of formulae II and III may be prepared. Thus, for certain compounds subgeneric to formula V, viz formula V-b as defined below, the tricyclic benz[e]indenes of formula I may be prepared by means of the building in an annulation reaction steroidal ring B. Alternatively, for certain other compounds subgeneric to formula V-a as defined hereinafter, the steroids of formulae II and III may be prepared by building by means of compounds of formula V-a, steroidal rings A and B. Thus, the keto compounds of formula V are employed as one of the starting reactants for the preparation of the tricyclic compounds of the formula I or the tetracyclic compounds of formulae II and III. However, it will be appreciated that the length of the carbon chain varies as exemplified by formulae V-a and V-b below, depending on which class of end products are sought to be prepared. Thus, the B-keto esters and analogs thereof of formula V-a below, are employed wherein it is desired to prepare the tetracyclic steroids of formulae II and III.

CH .CH CHg CH S )O l 5 dill-I3 wherein R R B, R and R are defined as aforesaid.

The B-keto esters and other analogs of formula V-a can be prepared in accordance with Reaction Scheme C below in which a specific embodiment is illustrated. The B-keto esters of formula V-a-l can be prepared from the hexanoic esters of formula X via process route (a) by reaction with base, preferably, lithium hydroxide in a lower alcohol solvent, e.g., ethyl alcohol at the reflux temperature of the solvent to form the salt of the acid by saponification of the ester. Subsequent reaction of the thus obtained salt with equimolar quantity of an organo metallic compound, preferably, methyl lithium in tetrahydrofuran in the presence of a minute amount of triphenylmethane yields the compounds of formula XII. In effecting the conversion, R should be in a protected keto form, e.g., ketal, the conversion to which has been herein before described. Alternatively, the compounds of formula XII can be prepared in accordance with Reaction Scheme C, via process routes'(b) and (c) by reacting the compounds of formula X with a lower alkyl sulfinyl methylene compound, e.g., methyl sulfinyl carbanion [cf., E. 1. Corey and M Chaykovsky, J. Am. Chem. Soc. 86, 1639 (1964)] to yield intermediates of formula XI.

Reduction XII 2 V-a-l 17 wherein R R R and R are defined as aforesaid and R is lower alkyl or aryl.

The compounds of formula XI can if desired, be oxidized to the sulfonyl derivatives with an oxidizing agent such as, for example, potassium permanganate. Reduction of the thus obtained sulfoxides of formula XI with a reducing agent, preferably, aluminum amalgam, yields compounds of formula XII. The compounds of formula XII can be converted to the B-keto esters of formula V-a-l via a Claisen Condensation with a carbonate of the formula wherein R is aryl or lower alkyl in accordance with process route (e). The preferred condensing agent is sodium hydride although alkali lower alkoxides, e.g., sodium alkoxide may also be suitably employed. The reaction is conveniently conducted in an ether solvent such as, for example, diethylether or tetrahydrofuran, the former being preferred at the reflux temperature of the solvent.

Illustrative of the ,8keto ester and other analog compounds of formula V-a which may be employed as starting reactants wherein it is desired to prepare the steroids of formulae II or III include 6-(2-methyl-l,3- diox0lan-2yl)-3-oxohexanoic acid ethyl ester; 6-(2- ethyl-l,3-dioxolan-2-yl)-3-oxohexanoic acid ethyl ester', 3,7-dioxo-octanoic acid methyl ester; 6-(2-methyll,3-dioxolan-2-yl)-3-oxohexanoic acid propyl ester; 3,7-dioxodecanoic acid ethyl ester; l-methylsulfinyl-S- (Z-methyl-l ,3-dioxolan-2-yl)-2-pentanone and the like. By referring to the general formula IV, it can be thus appreciated that when it is desired to prepare the steroids of formula XVII, the selections of the variables of formula V should be as follows: R is E 'CH .CH. CT'IQ and R R R and B are defined aforesaid.

The ,B-keto esters and other analogs of formula V-b below, are employed wherein it is desired to prepare the tricyclic compounds of formula I Rg- "B wherein R and B are defined as aforesaid.

The compounds of formula V-b, for example, ethyl propionyl acetate, may be prepared in a similar manner to the compounds of formula V-a in accordance with process step (e) by employing in Reaction Scheme C (the Claisen Condensation Step) butanone in lieu of the compounds of formula XII.

Exemplary of the B-keto ester and other analogs of formula V-b which may be employed as starting reactants wherein it is desired to prepare the tricyclic compounds of formula I include ethyl propionyl acetate, methyl propionyl acetate, ethyl aceto acetate, ethyl butyro acetate, butyro acetonitrile, acetoacctonitrile. l-methyl-sulfinyl-2-butanone and I'methyI-suIfonyI-Z- pentanone. 0

While certain groups exemplified by the definition of the term B have been illustrated in the l3-keto ester and other analogs of formulae V-a and V-b, it is to be understood that any other equivalent electron withdrawing group or groups of electrophilic nature can function as well. All that is required for the B segments of the molecule for the process of the reaction of the compounds of formulalV with the compounds of formula V is that it function efficaciously in this process aspect, that is, that it be a suitable electron withdrawing group so as to activate the hydrogen atom on the methylene group next adjacent to the carbonyl group. Preferred electron withdrawing groups are the alkoxy carbonyl esters, especially ethoxy carbonyl. The B-keto nitriles, e.g., aceto-acetonitrile of formula lV-b may be prepared by reaction of acetonitrile phenyllithium and diethylamine at a temperature range of-l()C to +l0C and hydrolyzing in dilute acid the thus obtained imine intermediate to the desired product [cf., Ann. 504, 94 (l933)]. The compounds of formula. V-a and V-b wherein B is defined as lower alkyl sulfinyl methylene and lower alkyl sulfonyl methylene can be readily prepared from the esters of formula V-a-l in a similar manner to that employed in process. step (b)iof Reaction Scheme C.

In a further aspect, the synthesis of the present invention relates to the preparation of steroids of the formulae II and III in accordance with Reaction Scheme 8 by means of reacting a carbon chain of the formula V-a with a bicyclic compound of the formulae IV-a or IV-c. In Reaction Scheme D, the numbers are assigned to Roman numerals for identification. schematically, the sequence of reactions involved in the synthesis of a specific embodiment, namely, l9-nortestosterone is illustrated.

In the Michael addition, process step (a) of Reaction Scheme D, the precursors to the steroidal A and B rings are built up in a single annulation reaction. The reaction is conducted in the presence of a base sufficiently strong to form the anion of the ,B-keto ester. Exemplary bases are for example, alkali metal lower alkoxides such as sodium methoxide, sodium ethoxide, potassium methoxide, potassium tertiary butoxide and the like; alkali metal hydroxides such as sodium hydroxide and the like; alkali metal hydrides such as sodium hydride, lithium hydride and the like; alkali metal amides such as lithium amide, sodium amide and the like; methyl sulfinyl carbanion (i.e., the anion from dimethyl sulfoxide). Especially preferred are the alkali metal lower alkoxides. The reaction can be conducted at a temperature range of from about 5C to about C. However, it is especially advantageous to conduct a reaction within a temperature range of from 0C to 25C. Moreover, the reaction is suitably conducted in the absence of oxygen for example, in an atmosphere of inert gas such as nitrogen or argon. It is convenient to conduct the reaction in the presence of an organic solvent inert to the reactants as well as the intermediates of formula XVI.

molar ratio of reactants of formulae IV-a-l and V-a-3.

One may add the reactant of formula V-a-3 to a reaction mixture already containing the bicyclic indanone of formula IV-a-l. However, the reaction can also be effected by placing all the reactants substantially together or preferentially the reactants of formula IV-a-l can be added to a mixture containing the reactants of formula V-a-3. When employing as a starting reactant, the compounds of formula IV-a in lieu of the reactants of formula IV-c-l the same process conditions are employed and products obtained although the reaction does not necessarily have to proceed by way of a Michael addition mechanism. The sidechain of the reaction intermediate XVI assumes the thermodynamically favorable equatorial configuration under the equilibrating reaction conditions. The alpha orientation of the sidechain is extremely important for the construction of ring B with the proper stereochemistry. No ring closure occurred at this stage because of the preferred enolization of the keto group towards the ester function. Following the Michael addition of the B-keto ester of formula V-a-3 to the bicyclic C/D-trans-indanone of formula IV-b-l, the thus obtained compound of formula XVI is saponified to remove the ester group and cyclized in accordance with process step (b) of Reaction Scheme D. The cyclization should be effected under reaction conditions which do not cleave the cyclic ketal protecting group. Exemplary basic cyclization reagents are for example, a dilute aqueous solution of alkali or alkaline metal hydroxides such as for example, sodium hydroxide, lithium hydroxide, calcium hydroxide and the like. The cyclization is suitably conducted in an inert organic solvent such as for example, hydrocarbons, e.g., benzene, toluene and ethers, e.g.,

tetrahydrofuran. The cyclization can be conducted at room temperature or above room temperature but as a matter of convenience, it is preferable to conduct the reaction at about room temperature. The ester group of the bicyclic intermediate of formula XVI can be removed by saponification of the ester inaccordance with Step (b) of Reaction Scheme D to afford the corresponding acid of the formula XVII (after acidification) and decarboxylation to compounds of the formula XVII-l for example, in refluxing toluene under an inert atmosphere such as for example, nitrogen in accordance with Step (c) of Reaction Scheme D. For other cases wherein the electron withdrawing group of formula V (B) is other than ester, e.g., for example, lower alkyl sulfinyl methylene or lower alkyl sulfonyl methylene, the removal of the grouping can be effected by reduction with a reducing agent such as, for example, aluminum amalgam. For cases wherein the electron withdrawing group is nitrile, the reaction can be suitably conducted in an analogous manner to that wherein the electron withdrawing group is an ester as discussed above.

The hydrogenation of the A -double bond of the compounds of formula XVII-a to the compounds of formula XVIII can be effected in accordance with Step (d) of Reaction Scheme D in a lower alcohol solvent such as, for example, ethyl alcohol in the presence of a base, preferably, triethylamine. l9-Nortestosterone can be obtained from the compounds of formula XVIII by hydrolysis of the tertiarybutyl ethercyclization by refluxing in a mineral acid such as, hydrochloric acid or sulfuric acid in a lower alkanol solvent such as methanol in accordance with Step (e) of Reaction Scheme D. 1

It should be noted that the process steps exemplified in Reaction Scheme D can be utilized to prepare norgestrel. This can be effected by preparing the 7aB- ethyl analogs of formula IV-a-l as described onpage 9 of the instant specification employing the reaction steps (a), (b), (c), (d) and (e') of Reaction Scheme D followed by oxidation utilizing for example, Jones Rea- 3,897,460 21 22 gent and ethinylation in accordance with procedures butoxide in benzene. The l7-hydroxy diene steroids of described on page 49 of the instant application. It will formula Ill-b are obtained in accordance with Step (e) be further appreciated that by employing the optically of Reaction Scheme E by refluxing in methanol in the active 7aB-ethylenantiomer of formula IV-a-l of Reacpr s n e of a p a y yd g n rid o t t l REACTION SCHEF'E E Q l l tii-t-butyl l I/ 1 I l H e\-/;;- l, E

N44 002 02.11 a) a '2 4b) V-al (\L/ vogcgi'b XVI-a t-but l f q-e-bue i (f o l a t i a n [cl Y.

,3 e; i 3 l. III-e tion Scheme D, one can prepare optically active The keto compound XVII-l of Reaction Scheme D norgestre]. can also be converted to steroids of the formula-XVII- It will be appreciated that this aspect of the process l-a via mild hydrolysis of the ketal moiety employing of the invention for the synthesis of steriods of the for- 0,] N hydr chloric acid in a solvent such as tetrahydr mula II of which l9-nortestosterone is a specific exemfuran t a temperature f approximately 20Ci aooorplar as set forth in Reaction Scheme D, can be modified 5 danoo i h S (f) f R ti S h e E St id of so as to yield other pharmaceutically valuable steroids F l II! can b v t d t h ma uti lly v l Of formula I], well known in the art, wherein R1 is other able estrogens by known means velluz et Anthan hydrogen, e.g., lower alkyl by selectively alkylatgowandto Ch i 72, 725 (1960),

ing the A -Compounds o formula XVII-1 with a In a further aspect, the present invention relates to lower alkyl halide in the Presence Ofa Strong base, P 4 the preparation of A, A -steroids of the formula Ill erably lithium in liquid ammonia at temperatures in the b reacting a vinylogous beta keto ester or other anaorder of 40C in an inert solvent such as, for example, l f th f l V Y diethyl ether by means known in the art.

Moreover, when R of the B-keto ester or other analogs thereof of the formula IV-a is oxo and not in aprotected ketal form, A, A -steroids of formula III in lieu of the steroids of formula II will be produced in accordance with Reaction Scheme E. Thus, in a specific embodiment exemplified in Reaction Scheme E, ste- E 2 I roids encompassed by the genus of the formula III are prepared. The dione ester of the formula V-a-4 is reacted with the methylene ketal of formula IV-a-l in accordance with Step (a) in the presence of an alkali alkoxide such as 0.1 N sodium methoxide in a methanol 5 solvent using a temperature range of 020C to yield wherein B is defined as aforesaid the substituted trione of formula X-Vl-a. The comwith compounds of the formula lV-a and IV-c. pound of formula XVII-a in accordance with Step (b) A preferred value of B is lower alkoxy carbonyl-Esof Reaction Scheme E can be hydrolyzed and ring pecially preferred is methoxy carbonyl and ethoxy carclosed using a hydrogen halide acid such as hydrogen 6O bonyl. Thus, in a specific embodiment exemplified in bromide in an acetone solvent at a temperature of ap Reaction Scheme F, diene steroids of the formula Ill-b proximately 20C to yield the" acid compound XVII-a. are prepared. The vinylogous beta keto ester. of for- Decarboxylation of compound XVII-a in refluxing tolumula Vl-a is reacted with the methylene ketone of forene in accordance with Step (c) yields compound mula IV-a-l in accordance, with Step (a) of-Reaction XVIl-l-a. The diene steroids of the formula III-a can be Scheme F in the presence of alkali lower alkoxide, prefobtained in accordance with Step (d) of 7 Reaction erably 0.1 Nsodium methoxide in a lower alcohol sol- Scheme E by cyclizing the compound of formula XVIlvent, preferably, methanol or ethanol, at a temperature l-a using an alkali alkoxide preferably potassium trangeof 0 to 20C yielding the dione of formula XXIII.

The diene steroid of formula III-b can be conveniently obtained from the compound of formula XXIII by cyclization using refluxing mineral acid, preferably, l-N- hydrochloric acid in a lower alcohol solvent, preferably methanol.

In still another of this invention, compounds of the formula IV-f, in Reaction Scheme A, can be converted to compounds of the formula XXIII below, which are subgeneric to ,thecompounds of formula IV XXIII wherein R,,,-Z and m are as definedaforesaidby decarboxylation in-a refluxing solvent such as, for example, tetrahydrofuranor toluene with or without a strong mineral acid, e.g., hydrochloric acid.;,The novel C/D-trans bicyclic indanone of compounds of formula XXIII are themselves useful intermediates in a total steroidal synthesis by employing, e.g. the methods described by R. E. Ireland and M. Chaykovsky, J. Org. Chem. 28, 748 (1963) the compounds of formula XXIII can be converted to their A acid analogs by a bromination-dehydrobromination procedure. The A -C/D trans indanones can be converted by methods described in the above cited reference to the tricyclic compounds of the formula I which in turn can be converted to pharmaceutically valuable steroids by procedures hereinafter described.

In a further aspect, the synthesis of the present invention relates in accordance with Step (11) of Reaction Scheme B to the preparation of 2,3,3a,4,5,7,8,9,9a,9bdecahydro-3a-alkyl-7-oxo-lI-I-benz[e]indenes and 4,4- aB,4ba,5,6,7,8a,9,lO-decahydro-8aB-alkyl-3I-lphenanthrene-3-ones-which contain in the 3-position and 8-position, respectively, an .oxozsubstituent or a B-OR moiety wherein R hasthe meaning given in the text accompanyingformula I. Many members of this class of known compounds which are valuable intermediates inthe synthesis of steroids, for example, benz[e- ]indene derivatives contain asymmetric centers atpositions-9a,9b,3a andalso at the 3'-position.-if the substituent thereat is other than oxo. Thus, of the 3-oxo compounds, there are eight possible different stereoiol-t-butyl l somers, whereas of the compounds containing a 3-OR substituent, there are possible 16 stereoisomers.

In a preferred embodiment of this aspect, the synthesis relates to the preparation of the 9aB, 9ba,3aB- stereoisomers of the benz[e]indene series, its optical antipode and racemate thereof and in the case where the 3-substituent is other than oxo, the 9aB,9ba,3aB,3B-stereoisomer, its optical antipode and the racemate thereof. The corresponding phenanthrene-2-one s, i.e., 4aB,4ba,8aB-stereoisomers may also be prepared. The especially desired end-products of the synthesis of this invention are the (-)-enantiomers of the formula I wherein R R Z and m are as defined aforesaid. The compounds of formula I can be obtained by commencing the synthesis of this invention with an optically pure starting material of formula IV or by commencing the synthesis of this invention with a racemic ('i.e.', dl) starting material of the formula IV and effecting resolution at any intermediate stage or after the desired end-product of formula I has been obtained as the racemate. I

Referring to Reaction Scheme G, wherein the compounds are assigned Roman numerals for identification schematically,.the sequence of reactions involved in the synthesis of a specific embodiment, namely, the benz[e]indenes of formula I-a are illustrated. Thus, ethylpropionylacetate is reacted with a compound of formula IV-c-l wherein the leaving group X exemplified. is mesyloxy (compounds of formula IV-a-l can also suitably be employed) to yield compounds of formula XVin accordance with Step (a). Reaction conditions employed for this conversion are identical with that exemplified hereinabove in process step (a) of Reaction Scheme E for the preparation of compound XVLCompound of formula I-a is obtained in accordance with process step (b) via cyclization which includes an internal aldol condensation and dehydration using a strong mineral acid, e.g., 2N-hydrochloric acid in a lower alcohol solvent, e.g., methanol, at the reflux temperature of the solvent. The conversion of compounds of the formula XV of Reaction Scheme G to compounds of the formula I-a can also be conducted under reaction conditions employed in Steps (b), (c) and (e) of Reaction Scheme D. 7

As indicated above, the 2,3,3a,4,5,7,8,9,9a,8,9badecahydro-3aB-alkyl-7-oxo-lI-I-benz[e]indenes and the 4,4a,8,4ba,5,6,7,8,8a, 9,10-decahydro-8aB-alkyl- 3H-phenanthren-2-ones of formula I obtained by the process of this invention are useful as intermediates in the formation of the tetracyclic steroid nucleus in accordance with Reaction Scheme F.

REA .3 p tw Preparation i CH3CH 0001130020235 1 H Elia-050 0113 V-a-Q F l l tive of methods to effect conversion of the tricyclics of 50 formula I to known steroids of which US. Pat. Nos. 3,115,507; 3,120,544; 3,128,591; 3,150,152 and 3,168,530 are exemplary.

The ultimate utility of the tricyclic intermediates depends on the nature of R and R For example, compounds wherein R1 is hydrogen may lead to either 19- nor steroids (Velluz et al., Angewandte Chemie 72, 725, (1960);'or alternatively to l0a-l9-nor-steroids (French Pat. No; 1,360,55) depending upon the reaction conditions. Further, the tricyclics wherein R is hydrogen maybe converted into;.19-nor-retro(9B,l0a)- steroids (Velluz et al. Tetrahedron Suppl. 8, Part II, 495 (19166) and estrogens, viz' compounds having an aromatic A ring e.g., estradio1'("Velluz-et al., Angewandte Chemie 72, 725(1960). On the other hand, compounds wherein R is alkyl may leadto compounds of the 9a,10a-series (Velluz et al., Angewandte Chemie 77, 185, (1960) or alternatively to compounds of the retrosteroid series viz those having inverted centers of asymmetry at positions C and C i.e., the 9,8,l0a-steroids (Belgium Pat. No. 663,193). Compounds wherein R is lower alkyl may be obtained wherein R of the compounds of formula V-b is lower alkyl (other than methyl).

As illustrated by the following Reaction Scheme H, in the first step of this reaction, the cyclo-olefin I may be hydrogenated to the tricyclic compound XIX. The reaction is preferably effected with a noble metal catalyst, e.g., a palladium-charcoal or a lower-rhodium charcoal catalyst. In formula XIX, R represents hydrogen or lower alkyl. Thus, compounds of formula I wherein R, represents hydrogen or alkyl can be hydrogenated to the compounds of formula XIX. The conversion of compounds of formula I to compounds of formula XIX and of the latter to compounds of formula XXII are described in greater detail in Belgium Pat. No.

Tricyclic compoundsof formula I for values wherein R, is hydrogen may be converted by means known in the art to compounds of formula XXI wherein R, is hy drogen viz steroids of the 19-nor-10a-series. Further, the tricyclic compounds of formula I wherein R, is hydrogen may be alternatively converted to compounds of formula II viz the normal steroids of the 901,108- (normal-19-nor series). This is described more fully in Angewandte Chemie 77, 185 (1965), Velluz, Valls and Nomin and Angewandte Chemie 72, 725 (1960), Velluz et al.

A preferred procedure for converting tricyclic compounds of formula I wherein R is hydrogen to normal steroids of the 9a-l9-nor series of formula II can be ef 4- R1 l//Z\ l H l OH H inzl 1 1 I I ll I-l II "Normal" steroids "lOcu-Seri es steroid s For example. a tricyclic compound of formula I such as 2,3.3a.4,5.7,8.9a/3,9ba-decahydro-3aB-ethyl-3-oxo-7- oxo-lH-benz[e]indene may be reacted with for example, 4-chloro-2-tertiarybutoxy-butane in a suitable solvent such as, for example. dimethylformamide or di methylsulfoxide under a nitrogen atmosphere in the presence of a base such as, for example, sodium hydride or potassium tertiarybutoxide at a temperature range of between l5and 100 to yield the intermediate l0-[ 3-tertiarybutoxy-butyl]- l 3-ethyll 9-nor-desA- androst-9-ene-5, l 7-dione. This latter compound can be converted to norgcstrel by procedures described more fully in U.S. patent application of Gabriel Saucy, Ser. No. 679,989, filed on Nov. 2, 1967.

XXII

"Retro" st er-oid s 4-Halo-2-tertiarybutoxy may be prepared from 4- halo-Z-butanol by reaction of the latter compound with isobutylene in the presence of a mineral acid such as a sulfuric acid or hydrochloric acid at room temperature.

The tricyclic compounds of formula I for values wherein R is alkyl may be converted by methods known in the art to compounds offormula XXIlvi'z steroids of the ftretro v series via catalytic hydrogenation compounds of the formula'XIXi and base catalyzed reaction with for example. methyl vinyl'k'etone Compounds of formula I can also be directly reacted with for example, methyl vinyl ketone yielding a 5-hydroxy-tetracyclic compound of formula XX. These latter compounds can then be subjected to dehydration followed by hydrogenation or to hydrogenation followed by dehydration to yield a 9B,!Oaor 100:- steroids of formulae XXI and XXII. These procedures are described in greater detail in Netherlands OctrooiaanvrageNo. 6,412,939. Still other methods of utilizing compounds of formula I are described in the literature or in the patents.

Compounds of formula I when converted into com pounds of formula II wherein R is ethyl and R, is hydrogen and Z is carbonyl can be selectively alkynylated by a suitable organic metallic acetylide affording norgestrel l3,B-ethyll 7a-ethinyll 7-hydroxy-gon- 4-ene-3-one). The latter compound can also be prepared according to Reaction Scheme D (cf. Page 39 herein). Exemplary of the suitable alkynylating agents to effect conversion to norgestrel are the alkali acetylides such as lithium acetylide, potassium acetylide, so dium acetylide, etc. The reaction is carried out in the presence ofliquid ammonia in suitable solvent systems such as benzene or toluene. The alkynylation is cffected preferably at the reflux temperature of the reaction medium although temperatures from 60 to are suitable. Exemplary of other suitable reagents to effect the acetylenic addition are ethylaminediamine complex in dimethylformamide solvent and Grignard analogs such as mono and bis acetylene-magnesium halides by means known in the art.

Further, the l9-nor-compounds of formula II, wherein R is propyl are ovulatory inhibitors (cf., Tetrahedron Letters 127 (1961), Velluz, Nomine' et al.). Additionally, compounds of formula I wherein R is methyl and R is hydrogen have been converted to the series of formula II, specifically, l9-nortestosterone acetate, J. Org. Chem., 26, 3904 (1961 L. J. Chinn and H. L. Dryden.

Moreover, compounds of formula I wherein R is ethyl and R is methyl and m is equal to 2 can be converted to compounds of formula XXII, i.e., l8-homoretrosteroids, specifically the acetyl derivatives of the pregnane series, which are progestational agents and are thus useful in the treatment of fertility disorders. The l8-homo-retroandrostanes of this series have both anti-estrogenic and anti-androgenic activity effecting the secretion of gonadotropic hormones. Hence, these compounds can be used for example, in the treatment of gynecological disorders and as contraceptive agents.

The methods of this invention, as indicated above, result in the preparation either of the desired optical enantiomer illustrated by formulae I and II or the racemate thereof. The optical antipode illustrated by formulae I and II can be obtained either by resolution of the corresponding racemic end product or by resolution of racemic starting material or, if racemic starting material is directly subjected to the methods of this invention, resolution of any intermediate racemate. The present invention provides a facile synthesis for opti cally active end products as a result of the fact that optical specificity is preserved throughout the synthesis as a result of the stereo selectivity of the individual process conversions exemplified in Reaction Schemes A, B, C, D, E and F. Resolution can be effected by conventional resolution means known per se. For example, compounds in which the moiety represented by the symbol Z is hydroxy-methylene, or a group convertible into hydroxy-methylene such as carbonyl (convertible by reduction to hydroxy-methylene) or an ether or ester of hydroxy-methylene (convertible by hydrolysis to hydroxy-methylene), can be resolved by reacting the compound containing the hydroxy-methylene moiety with a dibasic acid to form a half-acid ester. If the dibasic acids are, for example, dibasic-lower alkanoic. acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid or the like, or an aromatic dibasic acid such as phthalic acid, the so-formed half-acid ester is then reacted toform a salt with an optically active base such as brucine, ephedrine or quinine and the resulting diastereoisomeric products are separated. Alternatively, the hydroxy-methylene moiety can be csterified with an optically active acid such as camphorsulfonic acid and the resulting diastereoisomeric esters can be separated. The optical antipodes can be regenerated from the separated diastereoisomeric salts and esters by conventional means.

The following examples are illustrative but not limitative of the invention. All temperatures are stated in degrees Centigrade. Infrared. ultraviolet and nuclear magnetic resonance spectra where taken were consistent with stated structures. IR spectra where indicated were taken in chloroform. UV spectra where indicated. were taken in ethyl alcohol.

EXAMPLE i A 0.5 weight per cent solution of lB-tertiarybutoxy- 5,6.7,7a-tetrahydro-7aB-methyl-5-oxo-indane in absolute ethanol was hydrogenated at atmospheric pressure and room temperature using a It) per cent palladium/- CaCO catalyst. Hydrogenation was stopped after the uptake of 1 mole of hydrogen. The solution was then filtered and evaporated in vacuo to give a crude hydrogenation product. This crude product was then sub jected to hydrolysis by stirring and refluxing for 6 hours with a 1:1 mixture of tetrahydrofuran and 2 N hydrochloric acid under a nitrogen atmosphere. The solution was then cooled by means of an ice bath and neutralized with 5 N sodium hydroxide. The solvent was then evaporated in vacuo and the residue was extracted sequentially with ethyl acetate and then ether. The extract was washed with a saturated sodium chloride solution and then dried over sodium sulfate. Evaporation of the solvent in vacuo afforded a mixture of cis and trans reduction products 3aB.4.7,7a-tetrahydro-1/3- hydroxy-7a,B-methyl-5(6H)indanone and 3aa,4,7,7 atetrahydrol B-hydroxy-7aB-methyl-5( 6H )indanone which was analyzed by vapor phase chromatography and NMR. The vapor phase chromatography consisting of repeatedly subjecting the crude mixture of 3aB,4,7,- 7a-tetrahydrol fi-hydroxy-7aB-methyl-5(6H )indanone and 3aa,4,7,7a-tetrahydrol B-hydroxy-7afi-methyl- 5(6H)indanone to vapor phase chromatography in 40 milligram portions on a Barber-Coleman Model 5072 equipped with flame detection and a split ratio of 5:95. By this technique, 3aa,4.7,7a-tetrahydro-lB-hydroxy- 7aB-methyl-5(6H)indanone was obtained as an oil. 7 3620, 3300-3550 and 1715 cm in the infrared spectrum.

EXAMPLE 2 and the organic solventwas removed in-vacuo. The aqueous solution then extracted with'a mixture of ethyl acetate. and ether. The organic phase was washed with sodium bicarbonate and a saturated sodium chloride solution. The extract was dried over sodium sulfate and evaporated in vacuo to give the crude oxidation product 3aa,4,7,7a-tetrahydro-7aB-methyl 1 ,5- (6H )indanedione, as an oil. 68 Mg. of the crude oxidation product, 3aa,4.7,7a-tetrahydro-7aB-methyl-l.5- (6l-l )indanedione was subjected to vapor phase chro matography in 14 mg. aliquots on a Barber-Coleman Model 5072-eq'uip'ped with flame detection at a split ration of 5:95. Fractionation gave pure 3aa.4,7,7atetrahydro-7aB-methyl-l.5(6H)-indanedione, as an oil; 7 1740 and 1712 cm in the infrared spectrum. A sample was crystallized from ether-petroleum ether, m.p. 5253C.

EXAMPLE 3 45 Ml. of dimethylsulfoxide distilled from calcium hydride was added to a 53 per cent dispersion of 1.03 g. of sodium hydride in mineral oil which had been previously washed with anhydrous ether and dried under a nitrogen atmosphere. The mixture was stirred at 20C. and a solution of 5.0 grams of lB-tertiarybutoxy- 5.6,7.7a-tetrahydro-7aB-methyl-S-oxo-indane in 45 ml. of dimethylsulfoxide was added at once. The reaction mixture was agitated until hydrogen evolution ceased. approximately 4 hours thereafter. The dimethylsulfoxide wasthen distilled off under high vacuo utilizing a bath kept at a temperature of 75C, The residue (conjugate anion of 1B-tertiarybutoxy-5,6.7,7a-tetrahydro- 7a/3-methyl-5-oxo-indane) was dissolved in 90 ml. of

anhydrous ether and added as rapidly as possible (approximately 2 minutes) to a one liter flask containing a thick slurry of anhydrous solid carbon dioxide in 225 mlpof anhydrous ether. The reaction mixture was stirred vigorously. The slurry was formed by cooling 2-3 ml. of anhydrous ether with a dry ice-methanol cooling mixture and then permitting anhydrous solid carbon dioxide from an inverted tank of bone dry" carbon dioxide to enter. The tank was connected to the flask'with rubber pressure tubing. Two outlets were connected to two drying towers filled with anhydrous calcium sulfate. As the slurry formed and thickened, dry ether was added gradually from an addition funnel until a total of 225 ml. had been added. The reaction mixture was'stirred for 6 hours in a dry ice-methanol cooling bath'and allowed to stand at 20C for 16 hours. 200 Ml. of water containing 50 ml. of 0.1 N sodium hydroxide was added to the ether solution and it was agitated under a nitrogen atmosphere for l hour. The ether and water layers were separated and the ether layer was washed twice with water. The combined aqueous fractions were extracted with ether. The combined ether extracts were dried over sodium sulfate and evaporated in vacuo yielding starting material 1B- tertiarybutoxy-S,6,7.7a-tetrahydro-7aB-methyl-5-oxoindane. The aqueous solution was filtered and carefully acidified with 2 N hydrochloric acid to a pH of 2.5 at approximately C. The mixture was extracted twice with benzene and then with ether, washed with a saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in vacuo to yield a dry solid the B-keto acid, lB-tertiarybutoxy-S,6,7,7atetrahydro-7aB-methyl-5-oxo-4-indane-carbocyclic acid, m.p. l53.l60C. Trituration with ether yielded IB-tertiarybutoxy-S ,6,7 ,7a-tetrahydro-7aB-methyl-S- oxo-4-indane-carbocyclic acid, mp. 156C. An analytically pure sample of 1B-tertiarybutoxy-S,6,7,7atetrahydro-7aB-methyl-5-oxo-4-indane-carbocyclic acid was obtained by recrystallization from acetone,

mp 159.5C. Analysis calculated for C, H O C,

67.64; H, 8.33. Found: C, 67.63; H, 8.62.

EXAMPLE 4 1.84 Grams of unsaturated B-keto-acid 1B- tertiarybutoxy-S,6,7,7a-tetrahydro-7aB-methyl-S-oxo- 4-indane-carbocyclic acid was dissolved in 92 ml. of absolute ethyl alcohol and hydrogenated in the presence of 184 mg. of 10 per cent by weight palladium on barium sulfate catalyst at atmospheric temperature and room temperature. The theoretical amount of hydrogen was consummed in minutes. The solution was filtered and evaporated in vacuo, affording 1B- tertiarybutoxy-3aa-4B-5,6,7,7a-hexahydro-7a,8-

) methyl-5-oxo-4-indane-carboxylic acid, m.p.

107.5109C. An analytically pure sample of 1B- tertiarybutoxy-3-aa-4B-5,6,7,-7a-hexahydro-7aB- methyl-5-oxo-4-indane-carbocyclic acid was obtained by recrystallization from ether, m.p. 1l4l14.5C.

Analysis calculated for C, H O C, 67.13; H, 9.02. Found: C, 66.95; H, 9.09.

EXAMPLE 5 30.7 Mg. of the B-keto acid 1/3-tertiary-butoxy-3aa- 413-5,6,7,7a-hexahydro-7aB-methyl-S-oxo-4-indanecarbocyclic acid was dissolved in 2.5 ml. of tetrahydrofuran to which 2.5 ml. of 2 N hydrochloric acid was added. The reaction mixture was refluxed under a nitrogen atmosphere for approximately 6 hours. It was then neutralized with 2 N sodium hydroxide and evaporated in vacuo. The residue was extracted with ether and the extract was washed with a small amount of saturated sodium chloride solution, dried over sodium sulfate and evaporated in vacuo to give bicyclic keto alcohol 3aa-4,7,7a-tetrahydro- 1 ,B-hydroxy-7aB-methyl- 5(6H)indanone as a waxy solid, mp. 4l-42C. NMR spectra superimposable to that of 3aa-4,7,7atetrahydro-1B-hydroxy-7aB-methyl-5(6H)indanone, as prepared in Example 1. Analysis calculated for C H o z C, 71.39; H, 9.59. Found: C, 71.11; H, 9.32.

EXAMPLE 5a 246 Mg. of (i)-1B-tertiarybutoxy-3aa,4B,5,6,7,7ahexahydro-7a,B-methyl-5-oxo-4a-indanecarboxylic acid was suspended in 6 ml. of concentrated hydrochloric acid and stirred under a nitrogen atmosphere for 2.5 hours at room temperature until the compound had thoroughly dissolved. The flask was sealed under a nitrogen atmosphere and permitted to stand for approximately 20 hours. The solution was then evaporated in vacuo at 30C. to give a mixture that crystallized to yield a tacky crystalline-type solid upon treatment with acetone. The solid was ground up in 1 ml. of ether and the supernatant decanted to give a crude product, melting point l02-lO4C. (dec.). Recrystallization from ether gave pure (i)-3aa,4fi,5,6,7,7a-hexahydro-1B- hydroxy-7aB-methyl-S-oxo-4a-indanecarboxylic acid, melting point 123C. (dec.).

EXAMPLE 6 1B-tertiarybutoxy-3aa,4B,5,6,7,7a-

2.95 G. of

I h'exahydro-7aB-methyl-5-oxo-4oz-indane-carbocyclic acid was dissolved in a mixture of 22 ml. of dimethylsulfoxide and 12.2 ml. of 36-38 per cent aqueous for maldehyde solution. 1.35 G. of piperidine hydrochloride was added and it was stirred under nitrogen for 3 hours. 9.35 Mg. of sodium bicarbonate in water (100 ml.) was added to the above reaction mixture. It was then extracted three times with benzene. The extract was washed with water and with a saturated sodium chloride solution, dried over magnesium sulfate, filtered and then evaporated in vacuo to give a crude 1B- tertiarybutoxy-3act-6,7,7a-tetrahydro-7aB-methyl-4- methylene-indan-S(41-1)-one, as an oil. The crude methylene ketone lB-tertiarybutoxy-3aa-6,7,7atetrahydro-7aB-methyl-4-methylene-indan-5 4H )-one was purified by preparative thin layer chromatography on silica gel with a fluorescent indicator. The sample was applied at the rate of 30 mg. per plate which measured 8 inches X 8 inches X 1 mm. thick. The development was carried out with a mixture of 92.5 per cent benzene and 7.5 per cent ethyl acetate. The area corresponding to the major component was mechanically removed from the plate and the adsorbent was suspended in ethyl acetate. Filtration through Celite was followed by evaporation in vacuo to afford pure 113- tertiarybutoxy-3aa6,7,7a-tetrahydro-7aB-methyl-4- methylene-indan-(4H)-one, as an oil which crystallized upon standing in a container filled with dry-ice, m.p. 42.S-44C. Analysis calculated for C H O C, 76.22; H, 10.24 Found: C, 75.32; H, 10.25.

EXAMPLE 7 410 Mg. of freshly distilled ethyl propionyl acetate was added to 1 15.2 mg. of the crude methylene ketone lB-tertiarybutoxy-3aa,6,7,7a-tetrahydro-7aB-methyl- 4-methyleneindan-5(4H)-one. The reaction mixture was cooled to 0C and 0.87 ml. of 0.1 N sodium methoxide in methanol was added while agitating under a nitrogen atmosphere. The reaction mixture was allowed to stand for approximately 18 hours at 0C and for an additional 4 hours at 20C. The mixture was cooled by employing an ice bath and neutralizing with 0.87 ml. of 0.1 N hydrochloric acid. The solvent was then removed in vacuo and the residue was extracted with methylene chloride. The extract was sequentially washed with water and with a saturated sodium chloride solution, dried with sodium sulfate, filtered and evaporated in vacuo to yield crude diketoester 2-(1/3- tertiarybutoxy-3aa-4B,5,6,7,7a-hexahydro-7aB- methyl-5-oxo-4-indanylmethy1)-3-oxo valeric ethyl ester.

220 Mg. of the B-diketoester 2-(1B-tertiarybutoxy 3aa,4l3,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4- indanylmethyl)-3-oxo'valeric acid ethyl ester was dissolved in 4 ml. of methanol to which 4 m1. of 2 N hydrochloric acid was added. The reaction mixture was stirred and refluxed under a nitrogen atmosphere for approximately 6 hours. The reaction mixture was then cooled by use of an ice bath and neutralized sequentially with 0.4 m1. of 19.5 N sodium hydroxide solution and then with 0.4 ml. of 1.0 N sodium hydroxide solution. The solvent was evaporated in vacuo and the residue was extracted two times with ethyl acetate and once with ether. The combined extract was washed once with water and then two times with a saturated sodium chloride solution. The combined extract was then dried over sodium sulfate, filtered and evaporated in ac id vacuo to give crude 2,3,3a,4,5,7,8,9,9aB,9badecahydro-3B-hydroxy-3aB-6dimethyl- 1 H- benz[e]indan-7-one, an oil that could be crystallized by seeding with an authenic sample. 109 Mg. of the crude BCD-tricyclic compound 2,3,3a,4,5,7,8,9,9aB,9badecahydro-3B-hydroxy-3aB,6-dimethyl-1l-lbenz[e]indan-7-one was purified by preparative thin layer chromatography on silica gel with fluorescent indicator. Filtration through Celite followed by evaporation in vacuo gave an oil which crystallized upon seeing with an authentic sample; trituration with a 2:1 mixture of ether gave pure 2,3,3a,4,5,7,8,9,9aB,9badecahydro-3B-hydroxy-3aB,6-dimethyl-1H- benz[e]indan-7-one, m.p. 13l-133C.

EXAMPLE 8 134 Mg. of the unsaturated B-keto acid, 1,8- tertiarybutoxy-S,6,7,7a-tetrahydro-7aB-methyl-5-oxo- 4-indane carboxylic acid was suspended in 5 ml. of ether. The suspension was cooled to 0C and 7.6 ml. of a solution of diazomethane in ether (0.076 mmoles/m.) was added dropwise while stirring. After approximately 10 minutes of stirring, the solution was then evaporated in vacuo to yield the methyl ester, IB-tertiarybutoxy- 5,6,7,7a-tetrahydro-7aB-methyl-5-oxo-4-indane carboxylic acid ethyl ester, m.p. 7376C. Recrystallization from petroleum ether (boiling point 3060C) gave analytically pure l,B-tertiarybutoxy-5,6,7,7atetrahydro-7al3-methyl-5-oxo-4-indane carboxylic acid ethyl ester, m.p. 76.577C. Analysis calculated for C15H24O41C, 68.54; H, 8.63. Found C. 68.41; H, 8.92.

EXAMPLE 9 50 Mg. of the acid, lfl-tertiarybutoxy- 3aa,4B,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4- indane carboxylic acid was dissolved in 1.0 ml. of ether. The solution was cooled to 0C and 1.05 ml. of a solution of diazomethane in ether (0.19 mmoles ml.) was added dropwise while stirring. After 15 minutes of stirring, the solution was evaporated to dryness to give the B-keto ester 1B-tertiarybutoxy-3aa,4/3,5 ,6,7 ,7ahexahydro-7a/3-methyl-5-oxo-4a-indane carboxylic acid methyl ester, m.p. 112.5-113.5C. Recrystallization from petroleum ether (boiling point 3060C.) gave analytically pure IB-tertiarybutoxy- 3aa,4,8,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4aindane carboxylic acid methyl ester, m.p. l13.0-1l3.5C. Analysis calculated for C d-1 0., C, 68.05; H, 9.28. Found: C, 68.09; H, 9.49.

EXAMPLE 10 54.4 Mg. of the unsaturated ,B-keto ester, 13- tertiarybutoxy-S,6,7,7a-tetrahydro-7aB-methyl-5-oxo- 4-indane carboxylic acid ethyl ester, was dissolved in 2.7 ml. absolute ethyl alcohol and hydrogenated in the presence of 18.2 mg. of 10 per cent palladium on hairium sulfate catalyst at atmospheric pressure and room temperature. Hydrogen uptake ceased after 15 minutes. The solution was filtered and evaporated in vacuo to give crude 1B-tertiarybutoxy-3aa,4fi,5,6,7,7ahexahydro-7aB-methyl-5-oxo-4a-indane carboxylic acid methyl ester.

EXAMPLE 11 41 Mg. of the B-keto ester, lB-tertiarybutoxy- 3aa,4B,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4aindane carboxylic acid methyl ester was dissolved in a mixture of 1.25 ml. of methanol and 0.55 ml. of trimethyl orthoformate. The solution was cooled with an ice bath of C and 0.26 ml. of 2N methyl sulfuric acid was added while stirring under nitrogen. After minutes at 0C, the mixture was allowed to stand at 20C for 16 hours. It was cooled with an ice bath and neutralized with 1 N sodium methoxide and methanol. The solvent was evaporated in vacuo and the residue was extracted with ether. The extract was washed with aqueous sodium bicarbonate and with a saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in vacuo to give 13- tertiarybutoxy-3aa,4B,5,6,7,7a-hexahydro-5,5- dimethoxy-7aB-methyl-4a-indancarboxylic methyl ester, an oil; 'y 1728 in the infrared spectrum.

EXAMPLE 12 160 Mg. of the ketal ester, lB-tertiarybutoxy- 3aa,4fl,5,6,7,7a-hexahydro-5,5-dimethoxy-7a/3- methyl-4a-indancarboxylic methyl ester was dissolved in 3.5 ml. of dry toluene. The solution was cooled to 0C and 4.5 ml. of a 20 per cent solution of diisobutyl aluminum hydride in toluene was added over a 5 minute period while stirring under nitrogen. After an additional 30 minutes at 0C, the mixture was allowed to stand at 20C for 16 hours. It was then cooled with an ice bath and 3.0 ml. of methanol was added carefully while stirring. After minutes at 0C, it was stirred at C for 1 hour. The crystalline precipitate was filtered through a pad of Celite and it was washed and extracted thoroughly with ethyl acetate. The filtrate was washed with a saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in vacuo to give IB-tertiarybutoxy-Elaa ,4B,5,6,7,7ahexahydro-S,5-dimethoxy-7aB-methyl-4aindanmethanol, an oil; y 3575 cm in the infrared spectrum.

EXAMPLE 13 31.6 Mg. of the ketal alcohol, lB-tertiarybutoxy- 3aa,4B,5,6,7,7a-hexahydro-5,5-dimethoxy-7aB- methyl-4a-indanmethanol was dissolved in 1.8 ml. of acetone. The solution was cooled to 5C and 0.2 ml. of distilled water and 0.03 ml. of 2 N hydrochloric acid was added while stirring. After 20 minutes, the reaction mixture was neutralized with 0.65 ml. of a saturated sodium bicarbonate solution. The acetone was evaporated in vacuo and the residue was extracted with ether. The extract was washed with a saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in vacuo to give IB-tertiarybutoxy- 3aa,4,8,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4aindanmethanol, an oil; y 3580 and 1695 cm in the infrared spectrum.

EXAMPLE 14 17.4 Mg, of the B-keto alcohol, IB-tertiarybutoxy- 3aa,4B,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4aindanmethanol was dissolved in 0.25 ml. of dry pyridine and cooled to 0C, 8.0 Mg. of methane sulfonyl chloride was added while stirring to 0.56 ml. of dry pyridine. The reaction mixture was then allowed to stand at 20C for 1.5 hours. It was evaporated to dryness in vacuo and the residue was dissolved in chloroform. The solution was then washed with water and a saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in vacuo to give 16- tertiarybutoxy-3aa,4fi,5 ,6,7 ,7a-hexahydro-7afimethyl-5-oxo-4a-indanmethanol methanesulfonate, as an oil; 'y 1705, 1353 and 1175 cm" in the infrared spectrum.

EXAMPLE 15 22.9 Mg. of the ,B-keto mesylate, lfl-tertiarybutoxy- 3aa,4[3,5,6,7,7a-hexahydro-7aB-methyl-5-oxo-4aindanmethanol methanesulfonate was dissolved in a mixture of 0.3 ml. of methanol and 0.3 ml. of anhydrous benzene. 59.5 Mg. of ethyl propionyl acetate and 0.7 ml. of 1.0 N sodium methoxide was added and the reaction mixture was stirred at 0C under nitrogen for 2 hours and at 20C for 16 hours. The reaction mixture was neutralized with 0.1 N hydrochloric acid and evaporated to dryness in vacuo. The mixture was then treated twice with toluene and taken to dryness under high vacuo to yield the diketo ester, 2-(1B- tertiarybutoxy-3aa,4B,5,6,7,7a-hexahydro-7aflmethyl-5-oxo-4-indanylmethyl)-3-oxo-valeric acid ethyl ester, as an oil.

EXAMPLE 16 23.8 Mg. of the crude diketo ester, 2-( 1B- tertiarybutoxy-3aa,4B,5 ,6,7 ,7a-hexahydro-7a,B- methyl-5-oxo-4a-indanylmethyl)-3-oxo-valeric acid ethyl ester was dissolved in 0.5 ml. of tetrahydrofuran, and 0.5 ml. of 0.2 N sodium hydroxide was added while stirring at 20C. under nitrogen. The reaction mixture was allowed to stand at room temperature for 16 hours. The solvent was then evaporated in vacuo, the residue was dissolved in water and extracted with chloroform to remove neutral material. The water solution was carefully acidified with 2 N hydrochloric acid and extracted with chloroform. The extract was washed with saturated sodium chloride solution, dried over sodium sulfate and evaporated in vacuo to give the crude fi-keto acid, 3,8-tertiarybutoxy-2,3,3a,4,5,7,8,9- ,9aB,9ba-decahydro-3 aB, 6-dimethyl-7-oxo-1 H- benz[e]inden-8a-carboxylic acid. 3B-tertiarybutoxy- 2,3,3a,4,5,7,8,9,9aB,9ba-decahydro-3a,B,6-dimethyllH-benz[e]inden-7-one was obtained from the above produced product by refluxing in toluene for 1 hour under a nitrogen atmosphere.

EXAMPLE 17 348 Mg. of the lithium salt of the ketal acid, 4-(2- methyl-l,3-dioxolan-2-yl)butanoic acid was dissolved in 5 ml. anhydrous tetrahydrofuran. The solution was cooled to 0C and 1.25 ml. of a 1.6 molar solution of methyllithium in diethylether was added dropwise over a period of 1 hour while stirring under a nitrogen atmosphere. The solution was allowed to rise approximately to 20C and kept at this temperature over a period of 2 hours. The reaction mixture was added to crushed ice and the organic solvents were removed in vacuo. The residue was extracted with ether, the extract was washed with a saturated sodium chloride solution, dried with magnesium sulfate, filtered and evaporated in vacuo to give crude 5-(2-methyl-l,3-dioxolan-2-yl)- Z-pentanone.

EXAMPLE 18 378 Ml. of dimethylsulfoxide which was distilled from calcium hydride was added to a 53 per cent dispersion of sodium hydride (29.2 g.) in mineral oil which had been washed with anhydrous hexane and dried under nitrogen. The mixture was stirred under nitrogen and heated slowly to 687lC. After 1.5 hours, the evolution of hydrogen ceased and a turbid grey solution of the sodium salt of the metal sulfinyl carbanion had formed. The solution was cooled to 18C and 60.6 g. of the ketal ester 4-(2-methyl-1,3-dioxolan-2-y1)- butanoic acid ethyl ester was added over a 40 minute period to the stirred solution at a rate such as to maintain the exothermic reaction temperature at 18-20C for one hour. The solution was poured on ice, neutralized with cold 1 N hydrochloric acid and extracted with chloroform. The extract was washed with a saturated sodium chloride solution, dried over magnesium sulfate, filtered and evaporated in vacuo to give an oil. Volatile impurities were then removed under high vacuo, bath temperature maintained at 80C to give the B-keto sulfoxide, l-methyl-sulfinyl--(2 methyl-1,3- dioxolan-2-yl)-2-pentanone. Analysis calculated for C H O S: C, 51.26; H, 7.74; S, 13.68. Found: C, 50.96; H, 7.55; S, 13.81.

EXAMPLE 19 46.2 Grams of aluminum foil was cut into approximately 3 qt. inch square pieces and placed into a 5 lit. three necked flask, fitted with a nitrogen inlet and held on a shaker in a fume hood. The aluminum cuttings were shaken with a solution of 2 lit. of 1 N aqueous sodium hydroxide for l-2 minutes, and the alkali was siphoned; the metal was washed two times with 2 lit. of water in an analogous manner. The metal was then amalgamated by shaking for seconds with 2 lit. of a 2 per cent mercuric chloride solution in water. The mercuric chloride solution was then siphoned off and the amalgam was washed twice with I lit. of ethyl alcoholand once with ether. All operations were conducted under a nitrogen atmosphere. 40.0 G. of the B-keto sulfoxide, l-methyl-sulfinyl-5-(2-methyl-1,3-dioxolan-2- yl)-2-heptanone was dissolved in a mixture of 2160 ml. of tetrahydrofuran, 240 ml. of water and 4 ml. of l N sodium hydroxide. The solution was added at once to the lialuminum amalgam and was shaken under a rapid stream of nitrogen for 2 hours to entrain the methyl mercaptan formed. The reaction mixture was filtered through a pad of Celite on a sintered glass funnel, and the gelatinous precipitate was washed thoroughly with ether. The mixture was concentrated in vacuo to a volume comprising 50 ml. and extracted with ether. The extract was washed with a sodium chloride solution, dried over sodium sulfate, charcoaled with Norit A, filtered and evaporated in vacuo to yield the cetal ketone, 5-(2-methyl-1,3-dioxolan-2-yl)-2-pentanone. Analysis calculated for C l-1 0 C, 62.76; H, 9.36 Found: C, 63.09; H, 9.42.

EXAMPLE 11.8 Grams (0.1 moles) of diethyl carbonate in 12.5 ml. of anhydrous ether was added to 4.55 g. (0.1 moles) of a 53 per cent dispersion of sodium hydride in mineral oil which was washed with anhydrous hexane and dried under nitrogen. This mixture was stirred under nitrogen and 8.6 g. (0.05 mole) of the ketal keand 200 ml. of ice water. The etheral'layer'was separated, and the aqueous layer was additionally extracted twice with ether. The extract waswashed with saturated sodium bicarbonate and with a saturatedsodium chloride, dried with sodium sulfate, filtered and evaporated in vacuo to give the crude B-keto ester, 6-(2- methyl-1,3-dioxolan-2-yl)-3-oxo-hexanoic acid ethyl ester, hp. 1 101 12C at 0.2 mm., Analysis calculated for C1zH2005: C, H, 8.25. Found: C, H, 8.38.

EXAMPLE 21 A mixture of 2.36 g. (0.01 moles) of freshly prepared crude methylene ketone, lB-tertiarybutoxy- 3aa,6,7,7a-tetrahydro-7aB-methyl-4-methyleneidan-5- (4H)-one and 2.68 g. (0.11 moles) of B-keto ester 6-(2-methyl-1,3-dioxolan -2-yl)-3-oxo -hexanoic acid ethyl ester was cooled in an ice bath. 20 Ml. of an 0.1 normal sodium methoxide solution in methanol was added to the above reaction mixture and thesolution was allowed to stand at 0C for approximately 64 ,hours and at 20C for about 4 hours. The pH of the solution was then adjusted to 7.5 by means of 0.5 N hydrochloric acid and the methanol was evaporatedin vacuo. The oily residue was dissolved in 77.5 ml. of tetrahydrofuran to which 77.5 ml. of 0.2 N aqueous sodium hydroxide was added. The reaction mixture was stirred at 20C under a nitrogen atmosphere for 6 hours. The tetrahydrofuran was evaporated in vacuo and the basic solution extracted with ether. The ether extract was then washed with water and a saturated sodium chloride solution, dried with sodium sulfate, filtered and evaporated in vacuo to give a neutral impurity. 42.5 Ml. of an aliquot of the aqueous basic solution was carefully acidified at 0C with 5.1 m1. of 0.5 N hydrochloric acid so as to attain a pH of 3.5. The reaction mixture was then immediately extracted with ethyl acetate and with ether. The combined extract was washed with saturated sodium chloride solution, dried over sodium sulfate, filtered and evaporated in vacuo to give the crude unsaturated B-keto acid, 3B-tertiarybutoxy- 2,3,3a,4,5,7,8,9,9a,6,9ba-decahydro-6-[2-(2-methyl- 1,3-dioxo1an-2-yl)ethyl]-3aB-methyl-7-oxo-1l-lbenz[elinden-Sa-carboxylic acid, an amorphous solid. A few drops of ether were added to the crude solid 33- tertiarybutoxy-2,3,3a,4,5,7,8,9,9aB,9ba-decahydro-6- [2-(2-methyl-1,3-dioxolan-2-yl)ethy1]-3aB-methyl-7- oxo-lH-benz[eI-inden-8a-carboxylic acid and it was kept at 10C for 72 hours. A large crystalline crop was formed, which could be purified by trituration at room temperature with petroleum ether (b.p. 30- -60C Recrystallization from ether gave analytically pure 3B- tertiary-butoxy-2,3,3a,4,5,7,8,9,9aB,9ba-decahydro-6- 2-( Z-methyll ,3-dioxolan-2-yl)ethyl]-3aB-methyl-7- oxo-1l-l-benz[e]inden-8a-carboxylic acid, m.p. 129C. 

1. A COMPOUND OF THE FORMULA
 2. The compound of claIm 1 wherein R4 is methyl.
 3. The compound of claim 1 wherein R4 is ethyl. 